Dessous, the Harvester of Blood, is a vampyre lord who owns some territory north of Castle Drakan. The player is told of Dessous by Malak, one of the four guardians of the Diamonds of Azzanadra, who wants him dead in order to claim Dessous' land as his own. In order to achieve this, Malak tells the player that Dessous guards the diamond and if they wish to retrieve it they must eliminate him; it is when the player encounters Malak after the fight that he confesses that he is the real guardian and that Dessous was just an enemy of his, and then gives the diamond to the player as a reward for their troubles.

Dessous' attack is one part magic, one part ranged (a swarm of bats) each of which does double 50s for a total of 100 life points. He mainly attacks with a much stronger and rapidmelee attack which hits up to 190. Using either Protect from Magic or Ranged will stop half of the damage done by the bats. Players are advised to use Protect from Melee and to take armour which is resistant to magic attacks. Another option is using Protect from Magic and your best melee armour, but this is not recommended due to the speed and accuracy of his melee attack. A third option is to bring splitbark armour or dragonhide armour, as it protects from melee, ranged, and magic attacks. If players try to hit Dessous from a long distance away, he will teleport closer to them, and if Dessous teleports three times in total he will get "bored of toying with you" and go back to his grave (this means you have to refill the silver pot and start the fight again). Melee attacks don't work well on him, so using powerful magic spells up close is a good strategy since he has a low magic defence. In particular, Dessous is known to be most weak to any of the air spells although other spells work comparatively well with a strong enough magic weapon. Another method that works well enough is to use fire blast and Protect from Melee to avoid his powerful melee attack; a decent player shouldn't need more than half an inventory of monkfish.

Because of his very fast attack speed, a ring of recoil is particularly effective in this fight.

Dessous' magic/ranged combination attack has a loud, piercing cry when he uses it, so it could help to turn off the sound effects so it doesn't distract players when fighting him.

If any part of the quest is not followed correctly (for example, if the pot is not blessed), Dessous will say "You will never defeat me" when reduced to 0 life points and regenerate all his life points, ready to fight again, so be careful! To avoid this keep full concentration at all times while making the blessed pot of blood.

The site of the fight is Dessous's Tomb, which is found in the south-east of Mort Myre, in an area called the Graveyard. To awaken him, players must use a blessed silver pot containing blood, garlic and spice on his grave.

Recommended route to Dessous' grave, from the secret entrance to the Myreque hideout.

On many computers his bat attack's sound effect may cause intense lag due to its spammy nature, due to this it is recommended to turn sound off when fighting him.

It is somewhat strange that Malak would want the land that Dessous owns, considering that it appears to only be a graveyard surrounded by deserted swampland. It is possible that the land is important because of its vicinity to Meiyerditch, or owning land is simply a status symbol among the vampyres, as blood tithes seem to be run by the house of Drakan regardless of location, and other exports of the region are of little interest to the Vampyres.

Although he is considered a powerful vampyre and stronger than most Vyrewatch he can be hit with normal weapons instead of only being able to be hit with blisterwood weapons and Flail of ivandis. This however may be due to the blessed pot weakening him.